Process of sizing and shaping.



A. F. ROCKWELL.

PROCESS OF SIZING AND SHAPING.

APPLICATION mum JAN. 10, 1908.

926,898, Patented July 6,1909.

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ALBERTF. ROCKWELL, for BRISTOL,- cONNEoTIcUT, ASSIGNOR TO THE NEW DEPAR-.TUBE MANUFACTURING COMPANY, OF BRISTOL, CONNECTICUT, A CORPORATION OFCONNECTICUT.

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Patented my a, 1909.

Application filed January 10, 1800. Serial No. 410,261.

Tocll 'whom itmay concern: I

(Be it known that I, ALBERT F. Roon- WELL, a citizen of the UnitedStatearesiding atBristol, county of Hartford,{ State of Connecticut,have invented a certain new and ed' while the article has the walls ofits re-.

useful Process of Sizingand Shaping, of which the following is a full,clear, and exact description, such as will enable others skilled in theart to which it apeprtains to make and use thesame, reference eing hadtOthe accompanying drawings, forming part of this Spe01fiC&tl0I1..

My invention relates to rocesses of sizing and shaping recessed metaarticles, such, for example, as rings and cylinders, the present processbeing particularly valuable when practiced upon articles which it isdesired to harden.

Heretofore it has'been customary to givedesired size and shape to therecesses of metal articles by accurately cutting or grind ing. Thisrequires skilful and careful work and is expensive. Furthermore, when itis desired that the articles be hardened, it has been customary to makethe article with its recess of desired size and shape, to then heat thearticleand to then cool it, as by sub'ecting it to an oil bath, thecooling belng e ectcess or recesses'unsuplported in any way. The resulthas beent at the articles warp more or less during cooling and theirrecesses lose their particular size and shape, so

that after hardening the hardened articles have to have their recessesaccurately ground or machined anew. One object of my invention is toprovide a process whereby a recess of exact size and shape can beinexpensively produced in a metal article. A further object of myinvention is to provide a process whereby a recessed metal article canhave its recess accurately sized and shaped during the 'rocessofhardening.

To these ends, and a so to improve generally upon processes of thecharacter indiarticle as a dished ring.

cated, my inventionconsists in the various matters 1 hereinafterdescribed and claimed.

In the accompanying drawings: Figure 1 represents one step of my processwhen practiced upon such an article as a cylinder; and Fig. 2relpresents such step of my process as preferab y practiced when appliedto such an In carrying out my process,.the article is first formed inany convenient manner, such, for example, as by machining, the recess inthe article being preferably of slightly smaller diameter than thefinished size. The article is then heated, whereby it expands, and inits expanded condition it is placed about a mandrel whose exteriorpresents the size andsha e desired of the recess in the finished prouct. Thev article is then permitted to cool about the mandrel and is,then removed therefrom. Ihave found that by this method the recesses canbe most accurately sized and shaped, requiring no machining orgrinding'after the article is removed from the mandrel. a

By initially forming the articles with their recesses of slightlysmaller diameter than is desired'of the recess-in the finished article,accuracy insizing the recess is rendered unnecessary in the operation ofcutting or otherwise initially producing the article, and

when the article is heated, the expansion is sufiicient to enable themandrel to be inserted in the recess of the then-heated article, thearticle cooling to the desired size and shape upon the mandrel. Thus Iam enabled to-eliminate the expense and time required to accurately sizeand shape the arti-- hen it 'is desired that the article be hardened,the foregoing process is carried out and proper steps are taken toinsure hardening, such as employing material that Wlll become hard bychilling while .upon the mandrel. In this way the article is not onlyhardened but when hardened its recess is given the desired size andshape, thus rendering unnecessary any subsequent machining or grinding.

In Fig; 1, A indicates the article operated upon which is shown in suchfigure as being the cylindrical race of a ball bearing. The referencecharacter 1 indicates the mandrel which is inserted in the recess ofsaid article and about which the article cools as previ- Ou'slyexplained.

In Fig. 2, the article to be operated upon is shown as the race ring Bof a ball bearing,"

this ring being dished in a Well understood manner to receive the balls.One mandrel entering the recess of the ring is shown at" 2, this mandrelbeing, under these conditions,

preferably :jplunger which bears against the ring and co es such ringbetween the plunger and a suitable worktable or other support 3. Thispressure assists in preventing warping of the ring when cooling.Preferably the worktable or support is formed with aprojection 4 uponit, this projection becoming a mandrel which enters a vortionof therecess of the rin as clearly s own, so that the ring cools a out the twomandrels 2 The foregoing process is an extremely simple and inexpensiveone to practice, and it has been found to produce most'accurate andsatisfactory results. Furthermore, when applied to articles beinghardened it eliminates the necessity of subjecting the'hardened articlesto the additional and relatively expenceases greater diameter than thefollowing-mentioned mandrel, inserting a mandrel in said recesswithoutstretching the latter, permitting said article to cool and thuscontract upon and about said mandrel, and then removing said articlefrom the mandrel; substantially as described.

2. The process of sizing and shaping recessed artlcles' which consistsin heating the article to be operated upon, and permitt' it to coolabout and upon a mandrel receir b d in the recess of said article andwhile said article is subjected to pressure; substantially as described.7 3. The process of sizing and shaping recessed artlcles which consistsin heating the article to be operated upon, permitting it to cool andthus contract about and upon a mandrel received in the recess of saidarticle, and simultaneously with said cooling subjecting the article topressure exerted in a line transverse to that of its said contractionabout the mandrel; substantially as de scribed.

In testimony whereof, I hereunto afiixmy signature, in the presence oftwo witnesses.

ALBERT F. ROCKWELL.

